Westermo IDW-90 - Manual (Page 13)

13 6620-2200
RS-422/485
Electrical specification
EIA RS-485
2-wire or 4-wire twisted pair
Data rate 300 bit/s – 115.2 kbit/s
Data format 7 or 8 data bits, Odd, even or none parity, 1 or 2 stop bits,
Σ 9 – 12 bits
Protocol Transparent
Retiming Yes
Turn around time 50 µs (half duplex)
Transmission range <1200 m, depending on data rate and cable type (EIA RS-485)
Settings 120 W termination and failsafe biasing 680 W
Protection Installation Fault Tolerant (up to ±60 V)
Isolation to Power port 3 kV
rms
50 Hz 1 min
ISDN 2 kV
rms
50 Hz 1 min
IO 2 kV
rms
50 Hz 1 min
Galvanic connection to RS-232
Connection Detachable screw terminal
Connector size 0.2 – 2.5 mm 2 (AWG 24 – 12)
Shielded cable Not required*
Miscellaneous Do not connect RS-232 and RS-422/485 simultaneously
* To minimise the risk of interference, a shielded cable is recommended when the cable is located inside 3 m
boundary to the rails and connected to this port.
The cable shield should be properly connected (360°) to an earthing point within 1 m from this port.
This earthing point should have a low impedance connection to the conductive enclosure of the apparatus
cabinet, or similar, where the unit is built-in. This conductive enclosure should be connected to the earthing
system of an installation and may be directly connected to the protective earth.